Synthesizing UV-Protective Compounds in Bacteria

Our first idea was to engineer the production of the Micosprine-like Amino Acids (MAAs) in E. coli. These compounds confer UV protection in Anabaena variabilis and are currently used in sunscreen that protects against the entire UVA and UVB spectrum. To obtain these compounds for use in industry, the current method is direct extraction from A. variabilis. To develop an alternate way of producing these compounds, genes coding for enzymes in their production pathways were taken from A. variabilis and cloned into E. coli using BioBrickTM techniques. The result: E. coli that can produce UV protectant compounds, which has several implications. E. coli are cheap, easy to produce, grow quickly, are preferred for use in industry, and can be grown up in giant bioreactors. Therefore the speed and ease at which MAA-producing bacteria can be grown, as well as the amount that can be grown would drastically increase. Additionally, promoters and mechanisms of down-regulation in E. coli are well characterized, making modification and control of the pathway much simpler. These parts could easily be employed in future experiments where increased UV tolerance is desired (for example, in the characterization of a UV-sensitive promoter). Alternatively, a skin-based, UV-protectant probiotic could eventually be developed if these parts are incorporated into a native, non-pathogenic skim bacterium chassis, such as Staphylococcus epidermidis. Imagine a “sunscreen” that grows naturally on your skin!

Goal:Clone multiple gene pathways from algal species into E. coli to produce natural UV-protective sunscreening compounds.

Background:Our research has focused on two novel biosynthetic pathways found in two distinct algal species. A pathway ending in the production of two UV-protective compounds, shinorine and mycosporine-glycine, was cloned from Anabaena varibalis. A second pathway leading to the production of the unrelated UV-screening compound scytonemin was cloned from Nostoc punctiforme. Our objective is to develop novel and effective production platforms for these compounds, some of which are currently used in expensive sunscreens and lotions. These compounds are used both for the UV-absorptive properties as well as their role as potent antioxidants.